Catch null IP addresses

If x-forwarded-for header is not present, use IP address in
request.getRemoteAddr()
Fix log query count/paging

Specify start offset and row count in the SOLR query, rather than paging through results
Addresses bug where only 10 rows were returned (because 10 is the default number of rows in the solr config)
Remove unused index parameter from LogEntry.getXml()
Fix count/start/total in logHeader